Electronic systems can often be implemented in a micro-electronic circuit that is typically referred to as an IC or integrated circuit. These electronic systems typically include a number of passive and active electronic components, including but not limited to: resistors, capacitors, inductors, logic gates, linear amplifiers, voltage regulators, signal processors and converters, to name a few.
External signal sources can be coupled to the inputs of integrated circuits to provide the necessary signals utilized within the integrated circuit. The external signal sources can be from any variety of sources including bench test equipment, line drivers, and other integrated circuits, for example. Every signal source includes a characteristic output impedance, while every input to an integrated circuit has a characteristic input impedance. For high frequency circuits, the coupling between the external signal source and the integrated circuit functions as a transmission line whose characteristic impedance is ideally matched to the source impedance of the external signal source. Optimal signal transmission is achieved when the various characteristic impedances of the external signal source, the transmission line, and the integrated circuit are matched to one another. However, mismatches in the relative impedances may result in undesirable signal reflections which can be problematic for the operation of the receiving integrated circuit.